Support device

ABSTRACT

A blood flow stimulating device including a boot including a sole and an upper; a sock disposed within the boot; and a bladder disposed within or on the sock, wherein the bladder is configured to undergo repeated inflation and deflation so as to stimulate blood flow in a wearer of the blood flow stimulating device, wherein the sock further includes a toe region, a heel region and a raised portion between the toe region and the heel region that, in use, reduces the distance between the sock and a foot of a wearer of the blood flow stimulating device at the raised portion of the sock.

FIELD OF THE INVENTION

The present invention relates generally, but not exclusively, to asupport device which enables offloading of a foot of the wearer. Thesupport device may also comprise a blood flow stimulating means whichassists in the blood flow of the wearer of the support device.

BACKGROUND OF THE INVENTION

Diabetics often experience poor blood flow, which is described asperipheral ischemia, and may also suffer the loss of feeling in theirextremities, known as peripheral sensory neuropathy. If there is loss offeeling in the foot, it is common for injuries to occur without a personsuffering from diabetes even noticing, which can result in what is knownas diabetic foot ulcer formation. Such wounds can become infected andthere is a possibility of the infection spreading to the bone or bloodstream which can be life threatening and/or can result in the need foramputation of the limb.

Accordingly, it is desirable to treat such diabetic foot ulcers asquickly as possible so as to reduce the chance of infection and anysubsequent spreading of the infection.

To allow the wound to heal, the wound must be kept clean and coveredwith an advanced wound dressing followed by a technique calledoffloading, which is well known in the art. Offloading is a techniquewhere, usually, a boot or cast is applied to the foot of a patient so asto immobilise the tri-axis ankle movement of the patient and takepressure off key areas of the sole of the foot.

In normal gait or chain motion, a line of maximum pressure can be mappedthrough the foot using commercially available test equipment, andtypically, this line shows where maximum pressures or “hot spots” willlead to skin breakdown in a diabetic patients. By controlling the lineof force/pressure by limiting the rotation of the sub talar joint,offloading redirects/redistributes pressure, and shear and frictionforces acting upon a wound that can reduce the chance of an ulcerhealing.

During a normal gait cycle, the foot undergoes tri-planar motion whichallows lateral heel strike, lateral loading of the fifth metatarsal andthen transfer of pressure to the medial side of the foot over the firstmetatarsal head and push off through the first toe. Such tri-planarmotion allows transfer of pressure from the rear foot to the fore footcreating a line of loading from the lateral to the medial side of thefoot. A sub talar joint (STJ) is responsible for the majority oftri-plane motion in the foot. If the STJ is restricted, the foot is notable to go through its normal range of the motion and the pattern ofloading alters, i.e. a restriction of ankle motion does not allow normalheel strike or toe off, and hip and knee flexion must increase to enablethe foot to lift off the ground. Also, with the ankle fixed, the entiresurface of the foot will load almost simultaneously as the rear foot andfore foot contact the ground together. This is one potential mechanismof offloading when using Total Contact Casting (TCC).

People who have a normal foot physiology, normal blood supply and tissueoxygenation are not likely to suffer from pressure hot spots that causetissue damage, unless they wear ill-fitting footwear. Clinicians oftenrefer to “The Gift of Pain”, which alerts non sensory neuropathysufferers to something being “wrong”; footwear being too tight or astone in your shoe for example. Many diabetic patients have lost thiswarning signal, and only realise they have a problem when the wound hasalready occurred.

In considering the diabetic patient as a whole, it is important torealise that they can suffer metabolic changes, leading to abnormalphysiology in the foot as the tendons and other structures are affected.These deformities give rise to pressure hot spots while walking andrepetitive stress can occur causing the skin breakdown in the form of adiabetic foot ulcer.

The pressures measured during normal walking are an indication of thestress areas of the foot. With the diabetic patient, the foot shape canchange, blood supply is often compromised, causing a reduced bloodsupply (and consequently lowered tissue oxygenation) to the affectedarea. This can result in an ischemic foot. With loss of feeling in thefoot, the pressure area or developing foot ulcer may not be noticed.

As well, a diabetic patient can also experience metabolic changes whichcan lead to deformities in the foot, e.g. claw toes caused by tendonshortening. These deformities give rise to pressure hot spots and, whenwalking, repetitive stress can occur causing skin breakdown in the formof a diabetic foot ulcer.

It is very important that offloading be applied to the diabetic footeffectively and safely. TCC has been the optimal therapy for offloadingdiabetic foot ulcers. However, this technique is not always used becauseof its many limitations. TCC requires a specialist and takes a long timeto apply. The cast must be reapplied at each clinic visit as it must beremoved to view the wound. Clinicians are also concerned that the hardcast could damage vulnerable skin. The quality of life issues with TCCinclude safety and obtrusiveness during sleep or when showering. Castscan cause trips and slipping. Furthermore, TCC casts often raise one leg4 cm or more above the level of the other leg. This may cause imbalancedue to the other leg not requiring a cast. TCC casts should not be usedwith infected Diabetic foot ulcers as the wound needs to be observed ona regular basis to ensure correct antibiotic therapy is reducinginfection. Around 50% of all diabetic foot wounds are infected and, assuch, the applicability of TCC casts is greatly limited.

Ankle Foot Orthoses (AFOs) may look similar to offloading devices, butthe material they are constructed from is not be sufficiently rigid toallow pressure redistribution/offloading to occur. As such, they arenever prescribed for this purpose clinically. Indeed the Medicarereimbursement authorities in the US have expressly forbidden theprescription of AFOs in the treatment of diabetic foot ulcers as theyhave no functionality.

AFOs are only prescribed for foot drop (the loss of muscle control dueto peripheral motor neuropathy or injury such as a stroke, which allowsthe toes to “dangle” creating a potential trip risk). Whilst manydiabetics may suffer from foot drop, the condition bears no relevance todiabetic foot ulcers, other than that the root cause for both conditionsis nerve damage. The rigidity of an offloader (e.g. a plaster of pariscast type offloader) is necessary to prevent the tri-planar anklemovements described above. Upon weight bearing, an AFO will flex andallow such a degree of movement as to defeat the controlled pressureredistribution achieved by a true offloading device.

An unrecognised side effect of offloading whilst treating diabetic footulcers is a reduced foot and leg pumping action with consequential bloodflow back to the heart. The offloading technique described above stopsnormal foot movements due to the immobilisation effect. These footmovements are important in helping the plantar foot pump, calf musclesand valves return blood flow through the veins back towards the heartagainst gravity. Accordingly, there is a need to help promote blood flowat the same time as providing the offloading technique described above.

SUMMARY OF INVENTION

There is provided a support device comprising: a support for, in use,engaging a wearer of the support device; a boot comprising a sole and anupper; and an offloader coupled to the support and coupled to the boot,wherein, in use, the support engages the wearer of the support device soas to enable offloading of a foot of the wearer and the offloader isremovably coupled to the boot and passes around the outside of theupper.

The support may further comprise a rigid member disposed within the soleand the offloader may be removably coupled to the rigid member.

The offloader of the support device may further comprise a pin (or aplurality of pins) which removably engages the rigid member via a recessin the sole.

The support device may further comprise a blood flow stimulating means.

The blood flow stimulating means may further comprise: a power supply; afluid pump; a fluid reservoir; a control means; and a bladder.

The power supply, fluid pump, fluid reservoir and control means may eachbe disposed either on or in the support and the bladder may be disposedwithin the boot.

The offloader may be disposed entirely outside of the upper.

In use, the support may engage the wearer's leg below the knee.

In use, the offloader may passes from a shin of the wearer to thelateral aspect of the boot.

The offloader may comprise a physiologically designed arc to avoidcontact with skin in an ankle area of the wearer.

The rigid member may stiffen the sole so that, in use, the likelihood ofpressure points occurring on the foot of the wearer is reduced.

The support device may further comprise a pedometer and a memoryconfigured to store data output by the pedometer. The pedometer readingscan be used by the attending clinicians to issue alarms to the patientif they walk more than is beneficial to wound healing.

The support device may further comprise a proximity sensor to detectwhen the support device is being worn and a memory configured to storedata output by the proximity sensor.

The memory may be further configured to store data output by the bloodflow stimulating means, and the pedometer. These two readings combinedgive the attending clinician information, not currently available in anyother device, that can assist the clinician advise the patient regardingadherence to prescribed therapy.

There is provided an offloader for use in the support device.

There is provided a support device comprising: a boot comprising a soleand an upper; a sock disposed within the boot; and a bladder disposedwithin or on the sock, wherein the sock further comprises a toe region,a heel region and a raised portion between the toe region and the heelregion that, in use, the reduces the distance between the sock and afoot of a wearer of the support device at the raised portion of thesock.

The bladder may abut against the foot when fully inflated.

The bladder may be disposed within or on the raised portion of sock.

The bladder may abut a plantar plexus of the foot when the bladder ispartially inflated or fully inflated.

The bladder may abut a medial plantar arch of the foot when the bladderis partially inflated or fully inflated.

The bladder may have a volume of 40 cm³.

The bladder may have a volume of up to 40 cm³.

There is provided a support device comprising: a proximity sensor; amemory for storing data; a support device for, in use, engaging a wearerof the support device; and an offloader coupled to the support andcoupled to the boot, wherein, in use, the support engages the wearer ofthe support device so as to enable offloading of a foot of the wearer,wherein the proximity sensor detects whether a wearer is wearing thesupport device and data produced by the proximity sensor is stored onthe memory.

The support device may further comprise a pedometer, the pedometer maydetect how many steps are taken when the support device is being wornand data produced by the pedometer may be stored on the memory.

There is provided a support device comprising: a proximity sensor; ablood flow stimulating means; a support for, in use, engaging a wearerof the support device; and an offloader coupled to the support andcoupled to the boot, wherein, in use, the support engages the wearer ofthe support device so as to enable offloading of a foot of the wearer,and wherein the proximity sensor detects whether the support device isbeing worn and the blood flow stimulating means is disabled when theproximity sensor does not detect that the support device is being worn.

The support device may further comprise a boot comprising a sole and anupper;

There is provided a support device comprising: a boot comprising a soleand an upper; and a temperature sensor disposed within the boot in or onthe sole and or upper configured to detect skin breakdown and/or alikelihood of skin breakdown on a foot of a wearer of the supportdevice.

The support device may further comprise: a support for, in use, engaginga wearer of the support device; and an offloader coupled to the supportand coupled to the boot, wherein, in use, the support engages the wearerof the support device so as to enable offloading of a foot of thewearer.

The offloader may be removably coupled to the boot and may pass aroundthe outside of the upper.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample only with reference to the accompanying drawings, in which:

FIG. 1a depicts a comparative example of an integrated offloadingdevice;

FIG. 1b depicts a comparative example of an offloading element;

FIG. 2 depicts an exemplary blood flow stimulating system;

FIG. 3 depicts an exemplary integrated offloading device;

FIG. 4 depicts an exemplary offloading element;

FIG. 5 depicts a schematic diagram of an alternative blood flowstimulating means;

FIG. 6 depicts exemplary timings and pressure values for a full cycle ofoperation of the blood flow stimulating means shown in FIG. 5;

FIG. 7 depicts the underside of an exemplary sock;

FIG. 8 depicts a side-on view of an exemplary sock;

FIGS. 9a to 9c depict another exemplary sock;

FIG. 10 depicts an exemplary sock;

FIG. 11 depicts a shin support structure connected to an offloadingelement, wherein the shin support structure has a proximity sensor and apedometer disposed in or on it; and

FIG. 12 depicts an exemplary boot comprising multiple temperaturesensors.

DETAILED DESCRIPTION

There is described in what follows a system which enables offloading andwhich also promotes blood flow.

Several embodiments of an integrated offloading device are describedherein and it will be understood that the various features of each ofthese embodiments, as described in what follows, are not necessarilymutually exclusive from one another and that these features can becombined in any feasible combination, as would be understood by a personskilled in the art.

Throughout the specification, it will be understood that the term “boot”is intended to cover every suitable item of footwear which can be usedin the conjunction with each of the devices described herein. Examplesof alternative items of footwear include, but are not limited to, boots,shoes, sandals, footwear comprising an upper 104 which extends above theankle, footwear comprising an upper which stops below the ankle andfootwear comprising an open or partially open upper.

FIG. 1a shows a comparative example of an integrated offloading device10 which provides both the offloading functionality as well as promotingblood flow. The integrated offloading device 10 comprises a shin supportstructure 14 connected to a sock (otherwise known as an innersole) 11via an offloading element (or offloader) 12. The offloading element 12is shown in isolation in FIG. 1b . The sock 11 is disposed on top of aplate portion 12 b of the offloading element 12 (shown in FIG. 1b ). Thelower half of the integrated offloading device 10 is configured to bedisposed within a boot (not shown). The lower half of the offloader canbe affixed to the boot within the boot, as described in detail below.

The shin support structure 14 comprises means for fixing the offloadingelement 12 to the shin support structure 14. The embodiment of FIG. 1ashows screws 15 disposed within slide fixing 16 such that the locationof the screws can be adjusted within a range of different positions, thescrews 15 engaging with the offloading element 12 so as to affix theoffloading element to the shin support structure 14.

The shin support structure 14 further comprises a module 17 whichcontains components which comprise part of a blood flow stimulatingmeans. The module 17 is connected to a conduit 18 which is in turnconnected to a bladder 19, disposed within or on the sock 11.

The conduit 18 may be made of a non-expandable material so as to reduceenergy loss in the blood flow stimulating means. Throughout thisspecification, non-expandable is intended to include any material whichdoes not expand under the pressures generated within the blood flowstimulating means described herein.

The offloading element 12 comprises a stem portion 12 a and a plateportion 12 b, as shown in FIG. 1b . The stem portion 12 a of theoffloading element 12 is fixedly attached to the shin support structure14. As shown in FIGS. 1a and 1b , the stem portion 12 a of theoffloading element 12 twists from a position in front of the tibia of awearer of the device, at its end closest to the shin support structure14, to a position flush with the side of the sole of foot of the wearerof the device. A padded fabric sleeve 13 may be disposed around theoutside of the stem 12 a of the offloading element 12, as shown in FIG.1a . The plate portion 12 b of the offloading element 12 comprises twoholes 31, as shown in FIG. 1b . The plate portion 12 b may be securelyfastened into the bottom of a boot (not shown) via the holes 31. Thesock 11 may then be placed on top of the plate portion 12 b of theoffloading element 12 (as shown in FIG. 1a ). In such an arrangement,the lower half of the stem portion 12 a and the entirety of the plateportion 12 b of the offloading element 12, as well as the sock 11, areconfigured to be disposed within a boot (not shown).

The wearer of the integrated offloading device 10 places a boot, towhich the plate portion 12 b of the offloading element 12 is securelyfastened, on their foot and affixes the shin support structure 14 belowtheir knee, such that pressure is transferred from their foot to theirshin when standing on the leg on which the integrated offloading device10 is being worn and preferably such that the knee is still able toflex.

The bladder 19 is disposed within or on the sock 11 and is arranged suchthat, in use, the bladder 19 abuts the plantar plexus or the a medialplantar arch of a foot of a wearer of the integrated offloading device10. The module 17 is connected to the bladder 19 via the conduit 18 andwhich is disposed on or in the shin support structure 14.

The module 17 may further comprise some of the components shownschematically in FIG. 2, namely an electric pump 26 connected to anenergy source 28, a controller 27, an atmospheric air inlet (not shown),a fluid reservoir 29, a first valve 24 and a second valve 23.

The components of FIG. 2 collectively form a blood flow stimulatingmeans.

The components of the parts of the blood flow stimulating means disposedwithin the module may be connected to one another by conduits and theseconduits may be made of a non-expandable material so as to reduce energyloss.

It will be understood that the term fluid is intended to include, but isnot limited to including, air.

As shown in FIG. 2, the electric pump 26, which is in fluidcommunication with the atmospheric air inlet (not shown), is in fluidcommunication with the fluid reservoir 29 via the first valve 24. Thefluid reservoir 29 is, in turn, in fluid communication with the bladder19 via the second valve 23 and the fluid conduit 18. The controller 27controls the electric pump, the fluid reservoir 29, and the second valve23. The first valve 24 may also be controlled by the controller 27, butmay alternatively be a non-electrical one-way valve. Under control ofthe controller 27, the electric pump 26 provides air to the reservoir 29pressurising the reservoir 29 via the first valve 24. The second valve23 enables short bursts of pressurised air to flow from the reservoir 29into the bladder 19 via conduit 18. The operation of the second valve 23is controlled by the controller 27—with reference to memory 27 a. Athird valve (not shown) may be provided to provide controlled deflationof the bladder 19. The third valve may also be a pressure relief valveconfigured to prevent over pressurisation of the bladder.

The fluid reservoir 29 is preferably pressurised such that it is able toproduce a sharp rise in pressure at the bladder 19 once the second valve23 is opened meaning that the bladder undergoes rapid inflation. Thethird valve is preferably configured like a bleed valve such that it canprovide for fairly rapid deflation of the bladder 19 (for example over aperiod of 3 to 4 seconds).

Rapid inflation of the bladder 19 followed by rapid deflation maximisesthe blood flow promoting effect of the bladder 19. Most commonly,intermittent plantar compression devices squeeze the plantar region overa longer period of time than the rapidly inflating bladder 19 describedherein. This rapid action of the bladder 19 delivers a spike rather thana hump of blood flowing back up the veins. This allows the blood totravel further upwards towards the heart.

Preferably, the second valve 23 is open for a sufficiently long periodso as to enable the portion of the bladder 19 abutting the plantarplexus/medial plantar arch to urge compression of plantar plexus veinslocated in the plantar arch region of the foot, such that the subdermalveins at least partially close, thus urging the blood contained thereinto return towards the abdomen. It is known that a period of compressionof around half a second is sufficient to improve venous drainage,especially if repeated on a regular basis.

Without wishing to be bound by theory, it is thought by the presentinventors that repeat compression of the plantar veins releases nitricoxide, a potent vasodilator, which subsequently opens up arteriolesbringing more oxygenated blood to the plantar area. It is known thatincreased oxygenation is beneficial to wound healing and, therefore, itis believed that the integrated offloading devices 10 described hereinpromote the healing of foot ulcers in this regard.

There are some drawbacks to the above described integrated offloadingdevice 10. The arrangement of the offloading element 12 is such that theboot must fit around the lower portion of the offloading element 12 asdescribed above. Accordingly, the boot would need to be substantiallylarger than conventional footwear so as to accommodate the lower half ofthe offloading element 12. Patients who are unaccustomed to wearinglarger footwear could find such a boot unwieldy and it could present atripping hazard.

Furthermore, patients who would use the integrated offloading device 10often have swollen feet and/or delicate skin. As such, if their skincomes into contact with any part of the stem portion 12 a of theoffloading element 12, even if the offloading element is padded asdescribed above, unwanted pressure points can arise as the offloadingelement 12 is made out of a highly rigid material, for example, steel.

The flat plate portion 12 b of the offloading element 12 can lead tohigh heel pressures being experienced by the wearer of the offloadingdevice 10.

Accordingly, there is a need to provide an improved integratedoffloading device which overcomes deficiencies in integrated offloadingdevices such as the device 10 described above.

There is described in what follows a system which enables a much smallerboot to be used in conjunction with an integrated offloading device andwhich obviates the risk of pressure points arising as a result of theoffloading element of an offloading device contacting skin on the footor ankle of a wearer of the integrated offloading device.

FIG. 3 shows an exemplary integrated offloading device 110. The devicecomprises a shin support structure 114, a sole 111 and an offloadingelement (or offloader) 112 disposed between the shin support structure114 and the sole 111.

The offloading element 112 comprises a stem portion 112 a and a lockingportion or pin 112 c, which removably engage the rigid member 100 via arecess 113 in the sole 111 of the boot 101, as can be seen in FIG. 3 andFIG. 4.

The top of the stem portion 112 a of the offloading element 112 engageswith the shin support structure 114 in much the same way as described inrelation to the integrated offloading device 10 shown in FIGS. 1a and 1b. The shin support structure 114 is also substantially similar to theshin support structure 14 as has already been described herein andcomprises the same module and components.

The offloading element 112 is preferably arranged such that it twistsfrom a position towards the front of the tibia of a wearer of thedevice, where it intersects with shin support structure 114, preferablyto a position flush with the outward facing side of the outside of theboot 101, as shown in FIG. 3.

Although FIG. 3 shows the lower part of the offloading element 112intersecting with the lateral part of the boot 101, the offloadingelement 112 may equally intersect with any part of the boot, forexample, the heel part or the medial part of the boot. It will also beunderstood that the offloading element 112 may extend between anysuitable point of the shin support structure 114 and any suitable pointof the outside of the boot 101 so as to provide for the offloadingfunctionality, as would be understood by the skilled person.

The boot 101 may be specially designed so as to minimise any internalabrasive forces when the boot 101 is being worn. For example, the boot101 may have no exposed internal stitching or seams capable of rubbingaway frail diabetic skin.

The boot 101 comprises a rigid member 100 disposed within the sole ofthe boot, as shown in FIG. 3. The rigid member comprises at least onefemale mating portion (the rigid member shown in FIG. 3 comprises twofemale mating portions) which engages with the locking portion or pin112 c of the offloading element 112.

As shown in FIG. 3, the twist in the offloading element 112 is such thatthe locking portion or pin 112 c is located at a lateral part of theboot 101. The locking portion or pin 112 c comprises at least one maleportion, each male portion entering through an orifice/recess 113 in thesole 111 of boot 101 and engaging with the female portion of the rigidmember 100 disposed within the sole 111 of the boot 101.

The nature of this engagement is such that sufficient rigidity isprovided to enable offloading of the foot, locking tri-axial anklemovement as described previously, of the wearer via the engagementsbetween the rigid member 100, the offloading element 112 and the shinsupport structure 114. By locking the ankle, pressure hot spots areprevented. Further, the speed of the “foot slap”, which creates peakpressures in the metatarsal area and toe extremities, is controlled.Limiting the movement of the ankle causes the less flexible knee and hipjoints to articulate to allow chain motion, but at a slower pace.

The design of the offloading device 110 addresses another concern thattroubles diabetic foot ulcer patients. Peripheral sensory neuropathyoften prevents diabetic foot ulcer patients feeling if their feet arecorrectly located in the footwear component. The offloading device 110design allows the boot 101 to be fitted correctly first, with visualsighting by the patient, then the shin support structure 114 and theoffloading element (or offloader) 112 can be fitted subsequently.Current designs of offloader interfere with clear sight of the footplacement within the device.

Advantageously, the offloading element 112 is not disposed within theboot 101 and the aforementioned issues arising in relation to thesubstantially rigid offloading element 12 being disposed against theskin of the wearer of the integrated offloading device 10, specificallythe skin around the foot and ankle, do not arise.

A sock 11 is provided within the boot 101 of the exemplary integratedoffloading device 110. As described in relation to the integratedoffloading device 10, the sock has a bladder disposed within or on itand the bladder is connected to the remainder of the blood flowstimulating means via conduit 18 (as shown in FIG. 2), the remainder ofblood flow stimulating means being located within the shin supportstructure 114. As such, the exemplary offloading device 110 alsoprovides for blood flow stimulation in conjunction with offloading.

Advantageously, the rigid member 100 stiffens the sole of the boot 101so that, in use, only very limited flex in the boot sole occurs,reducing the likelihood of pressure points occurring on the foot of thewearer of the integrated offloading device 110 as the line offorce/pressure during a gait cycle is controlled and spread out comparedto the line of maximum pressure during a normal gait cycle where anoffloader is not being used, which means that the maximum pressures or“hot spots”, which can lead to skin breakdown in a diabetic patients,are avoided.

After a course of treatment is completed, the shin support structure 14and the offloading element 112 may be removed. The boot 101 willcontinue to provide enhanced offloading capability over regular footweardue to the increased rigidity of its sole. As such, pressure, and shearand friction forces are reduced and the likelihood of the occurrence orreoccurrence of ulcers is reduced.

Another advantage is that the boot 101 can be used on its own (i.e.removing the offloading element 12 and shin support structure 14 after aperiod treatment), for example for treatment of acute conditions,meaning that the patient can be discouraged from going back to wearingill-fitting shoes and/or shoes with exposed internal stitching, capableof rubbing away frail diabetic skin when offloading is no longerrequired or possible.

It is a concern to skilled practitioners that providing a pair ofdiabetic boots that reduce the social stigma due to their normalappearance will encourage patients to walk more. The clinicalrecommendation to a diabetic foot ulcer patient wearing the currentinvention will be to wear it allowing blood pumping for several hoursper day, but not to walk unless absolutely necessary, so as to promotehealing of the foot ulcer. The clinician needs to be able to check thatthe patient is abiding by this advice.

The integrated offloading device 110 may further comprise a pedometerand a memory configured to store the data output of the pedometer.

The inclusion of a pedometer would enable a clinician to ascertain howmany steps the patient has taken during a treatment period.

The integrated offloading device 110 may also comprise a proximitysensor to detect whether the device is being worn or not and/or how manyhours pumping has taken place. This data may be stored on the memory anddownloaded at clinic or transmitted remotely to a clinician.

Advantageously, the inclusion of a proximity sensor would enable aclinician to ascertain how often the boot is worn during a treatmentperiod. This can be combined with data from the pedometer to ascertainhow many steps a patient has taken whilst wearing the integratedoffloading device 110.

The integrated offloading device 110 may be configured such that theblood flow stimulating means will not operate if the proximity sensordetects that the device 110 is not being worn.

Data from the controller 27 may also be stored on the memory such thatthe clinician is able to ascertain how often the bladder has inflatedduring a treatment period. Advantageously, this provides the clinicianwith means for measuring the compliance of a particular patient withregards to the treatment.

The integrated offloading device 110 may be used with a boot designedwith a rocker sole to allow better pressure distribution during normalgait.

Rocker bottoms, front and back, are well known to those skilled in theart.

A rocker sole has a toe section that is raised upwards, creating a gapbetween the ground and the sole of the footwear. For a diabetic withtri-axial ankle motion locked in an offloading boot, a rocker soleallows a small transfer of weight forward to create the start of thegait cycle, and reduce peak interface pressures at the toes. A rockerheel may also be provided to reduce downward pressure upon heel strike,transitioning into forward movement smoothly, thus preventing the footfrom slapping down.

The integrated offloading device 110 may be used with a boot whichfurther comprises straps designed to be easily secured by patients withpoor eyesight and limited grip strength. The straps may be double returnVelcro™ (hook and loop fastener) straps with a mid-point which givesusers a guide as neuropaths can't feel tightness as a normal personwould. The correct securing of the boot is important as the bladder 19will seek to lift the foot upwards unless constrained by the boot.

Neuropathic patients represent around 60% of patients with footulceration. They have no sensation in their feet, so often over tightenfootwear fastenings to the point where skin abrasion or even localischemia occurs. The boot 101 may have marked straps to give anindication as to how tight they should be in the absence of patientsensory feedback.

FIG. 5 is a schematic diagram of an alternative blood flow stimulatingmeans. Many of the components are the same as or similar to those of theblood flow stimulating means shown in FIG. 2 and the same referencenumerals have been used for these components.

The blood flow stimulating means comprising a module 17 comprising apump 26, a controller 27, a timer in communication with the controller27 a, a reservoir 29, a pressure sensor 51, a solenoid valve 52, a bleedvalve 53, and a pressure relief valve 54 which acts to keep the pressurebelow a predetermined upper threshold (for example, 23.4 kPa (3.4 psi)).Also shown is the conduit 18 which connects the solenoid valve 52 to thebladder 19. The controller 27 is in communication with the pump 26, thesolenoid valve 52 and the pressure sensor 51. The pump 26 is in fluidcommunication with the reservoir 29 and the solenoid valve 52. Apressure sensor 51 is in communication with the reservoir 29 such thatwhen the pressure in the reservoir 29 reaches a predetermined value (forexample, 94.5 kPa (5 psi)) the controller 27 switches the pump 26 offsuch that no more fluid is pumped into the reservoir.

The solenoid valve 52 is connected to the bladder 19, the reservoir 29and the bleed valve 53. As shown in FIG. 5, the solenoid valve 52 isable to switch between a configuration A-B where the bladder 19 is influid communication with the bleed valve 53 and a configuration A-Cwhere the bladder 19 is in fluid communication with the reservoir 29 viathe solenoid valve 52.

FIG. 6 shows exemplary timings and pressure values for a full cycle inthe operation of the blood flow stimulating means shown in FIG. 5. 601shows the position of the solenoid valve 52, 602 shows the pressure ofthe fluid in the reservoir 29 during a cycle between exemplary lower andupper values 23.4 kPa (3.4 psi) and 94.5 kPa (5 psi), 603 shows thepressure of the fluid in the bladder during a cycle between exemplarylower and upper values 0 kPa (0 psi) and 23.4 kPa (3.4 psi) and 604shows whether the pump 26 is switched on or off.

The cycle shown in FIG. 6 starts with the solenoid valve 52 in the A-Cposition. The previously pressurized reservoir 29 is thus in fluidcommunication with both the bladder 19 and the pressure valve 54. Thepressure of the bladder and reservoir is maintained at the exemplaryvalue of 23.4 kPa (3.4 psi) by the pressure relief valve 54.

Although an exemplary pressure of 23.4 kPa (3.4 psi) has been described,any suitable pressure, i.e. sufficient to produce the blood flowstimulating effect, may be used, as would be understood by a personskilled in the art.

At time X (1 second after the start time) the controller switches thesolenoid valve 52 to the A-B configuration where the bladder 19 is incommunication with the bleed valve 53. The pressure inside the bladder19 then drops to 0 kPa (0 psi) as the fluid inside of the bladder isreleased into the atmosphere via the bleed valve 53. Once the solenoidvalve 52 has been switched to the A-B position, the controller 27switches on the pump 26 and the reservoir 29 is pressurized to 94.5 kPa(5 psi). Once the reservoir reaches an exemplary predetermined pressureof 94.5 kPa (5 psi), the pressure sensor 51 communicates with thecontroller 27 signaling that the predetermined pressure has been reachedand the controller 27 switches off the pump 26. After a predeterminedperiod of 19 seconds since time X has elapsed, the solenoid valve 52 isonce more switched to the A-C position at time Y such that the bladder19 is put into fluid communication with the pressurised reservoir 29 andis inflated and the cycle repeats with the solenoid valve 52 being oncemore switched to the A-B after a predetermined period of time (forexample, 1 second) after time Y has elapsed.

The structure of the offloading element 112 is used to providestructural support to the conduit 18, which brings pressure from thereservoir 29 to the bladder 19. The conduit may pass through a channelin the outside of the sole 111 of the boot 101 to reach the bladder 19.

FIG. 7 shows the underside of an exemplary sock 11. FIG. 7 shows arecess 110 in the underside of the sock 11 for housing the bladder 19and the conduit 18.

FIG. 8 shows a side-on view of an exemplary sock 11 with the bladder 19inflated. The Figure also shows a foot in the position that it would bein when a user of the integrated offloading device 10 is wearing saiddevice. It is apparent from FIG. 8 that the inflated bladder 19 isabutting the plantar plexus/medial plantar arch of the foot.

FIGS. 9a to 9c show another exemplary sock wherein the sock is comprisedof a top 11 b, a middle 11 c and a bottom 11 d. FIGS. 9b and 9c show therecess 11 a for housing the bladder 19 and the conduit 18.

FIG. 10 shows an exemplary sock 11 e. The sock 11 e has a heel region1001 and a toe region 1002, as shown in FIG. 10. The heel region of 1001may be raised relative to the toe region 1002. This would act to tiltthe wearer forward slightly, thus taking pressure off the heel andproviding better weight distribution. Between the heel region 1001 andthe toe region 1002 of the sock 11 e is a raised portion 1003. Thebladder 19 a is disposed on the raised portion 103. The raised portion1003 may be designed to match the contours of the plantar plexus ormedial plantar arch region of a foot.

As can be seen in FIG. 10, the sock 11 e is disposed much more closelyto the underside of the foot of a wearer than the bladder shown in FIG.8. As a result, a smaller bladder 19 a can be used as, upon inflating,the bladder 19 a needs to cover less distance than the bladder 19 (shownin FIG. 8) as the bladder is disposed much closer to the foot of thewearer. As such, the use of a contoured sock such as the sock 11 e shownin FIG. 10 enables a bladder of a smaller volume to be used than isneeded for regular flat socks such as the sock 11 shown in FIG. 8.

Alternatively, the same or a similar sized bladder as is used with theflat sock shown in FIG. 8 can be used. When a foot abuts the sock 11 ewhen the boot 101 is being worn, such a bladder 19 would not need to beinflated fully before the pressure limit (for example, 23.4 kPa (3.4psi)) is reached as it would abut the foot of the wearer before it wasfully inflated causing the pressure in the bladder to increase sooner.

Accordingly, when a contoured sock such as the sock 11 e is used withthe blood flow stimulating means, less energy is required to operate theblood flow stimulating means as less fluid is being transmitted aroundthe system and the bladder 19 or 19 a can be inflated in a shorter spaceof time, both of which result in less fluid being transmitted from thereservoir 29 to the bladder 19 per cycle. Accordingly, the battery lifeof the blood flow stimulating means is increased.

The bladder 19 a may have a volume approximately of 40 cm³.

The bladder may have a volume of up to 40 cm³.

Pressure redistribution is also aided by the sock 11 e as it ensuresthat the plantar aspect of the foot is maximally supported, for exampleby raised portion 1003 of the sock 11 e or a foam, so that the surfacearea bearing the load is as large as possible, thereby ensuring lowestaverage pressures across the foot, reducing the likelihood of ulcerformation.

In order to overcome the problem of high heel pressures developing, asdescribed above, a swan line can be incorporated into the boot 101 ofthe integrated offloading device 110. A swan line is where the heel of awearer of the boot 101 is held in a position higher than the front oftheir foot. This would act to tilt the wearer forward slightly, thustaking pressure off the heel and providing better weight distribution.

The swan line can come from the shape of the boot 101 itself or from theshape of the contoured sock 11 e.

With regard to the previously described integrated offloading device 10,the flat plate portion 12 b, as shown in FIG. 1b , could be shaped suchthat a swan line is formed. Alternatively, the sock 11, disposed on topof the flat plate portion 12 b could be shaped such that a swan line isformed.

Accordingly, any of the integrated offloading devices 10, 110 describedherein could configured to include a swan line.

Although the use of contoured socks is known in footwear, the use ofcontoured socks in integrated offloading devices 110 is not obvious asthe foot is offloaded from the sock of the boot and the nature of thecontact of the foot with the sock is, therefore, less of aconsideration.

FIG. 11 shows a shin support structure 114 connected to an offloadingelement 112 wherein the shin support structure has a proximity sensor1101 and a pedometer 1102 disposed in or on it.

The proximity sensor 1101 is configured to detect when the shin supportstructure 114 is being worn. A memory (not shown) may be provided tostore data produced by the proximity sensor 1101. As such, a record ofhow often and when the shin support structure 114 is being worn can bekept.

The pedometer 1102 is configured to detect how many steps are taken by awearer of the shin support structure 114. Likewise, a record of how manysteps have been taken can be recorded on the memory.

The data recorded on the memory can be used by a clinician to monitorpatient compliance.

FIG. 12 shows an exemplary boot 101 comprising multiple temperaturesensors 121 a, 121 b and 121 c. These are disposed abutting the areas ofthe foot of a wearer that are most prone to skin breakdown.

A battery pack or other energy source (not shown in the Figures) forpowering the blood flow stimulating means may be disposed on the outsideof the shin support structure 114 such that it can be easily replacedwithout the wearer of the integrated offloading device 110 having toremove the shin support structure 114.

The proximity sensor 1101 and pedometer 1102 may be mounted in or on theshin support structure 114 and therefore they would be directly wired toor present on an electronics printed circuit board (PCB).

The temperature sensors 121 a, 121 b and 121 c that are in the footwearmay be connected to a local electronics PCB installed in the boot 101and the data from the sensors may be sent to the main PCB in the shinsupport structure 114 either by wired or wireless connection. The localelectronics PCB may be provided within the sock 11, 11 a, 11 b, 11 c, 11d and 11 e or within the sole 111 of the boot 101.

Although the present invention has been described in connection withspecific exemplary embodiments, it should be understood that variouschanges, substitutions, and alterations apparent to those skilled in theart can be made to the disclosed embodiments without departing from thescope of the invention as set forth in the appended claims.

The invention claimed is:
 1. An offloading support device, comprising: asupport for, in use, engaging a wearer of the support device; a bootcomprising an upper and a sole; a rigid member disposed within the sole;an offloader; a first coupling engagement between the offloader and thesupport, the first coupling engagement comprising a channel in thesupport that is configured to receive a top end of the offloader, and atleast one fastener to securely join the support to the offloader, thefirst coupling engagement being configured such that, upon insertion ofthe top end of the offloader into the channel and upon tightening of theat least one fastener, the support is rigidly fixed relative to theoffloader to prevent relative movement between the support and theoffloader; and a second coupling engagement between the offloader andthe rigid member, the second coupling engagement comprising a malemating portion on the offloader and a female mating portion on the rigidmember, the second coupling engagement being configured such that, uponinsertion of the male mating portion of the offoloader into the femalemating portion of the rigid member, the rigid member is rigidly fixedrelative to the offloader to prevent relative movement between the rigidmember and the offloader; wherein the first coupling engagement betweenthe support and the offloader, and a the second coupling engagementbetween the offloader and the boot, are both sufficiently rigid so as toimmobilize tri-axis ankle movement of a foot of the wearer when a heelof the wearer's foot is engaged with a corresponding heel portion of thesole.
 2. The offloading support device of claim 1, wherein the malemating portion comprises at least one extension configured to removablyengage the female mating portion of the rigid member via a recess in thesole.
 3. The offloading support device of claim 1, further comprising ablood flow stimulating system.
 4. The offloading support device of claim3, wherein the blood flow stimulating system comprises: a power supply;a fluid pump; a fluid reservoir; a controller; and a bladder.
 5. Theoffloading support device of claim 4, wherein the power supply, thefluid pump, the fluid reservoir and the controller are each disposedeither on or in the support and the bladder is disposed within the boot.6. The offloading support device of claim 1, wherein the offloader isdisposed entirely outside of the upper.
 7. The offloading support deviceof claim 1, wherein, in use, the support engages the wearer's leg belowa knee.
 8. The offloading support device of claim 1, wherein, in use,the offloader passes from a front of a shin of the wearer to a lateralaspect of the boot.
 9. The offloading support device of claim 1, furthercomprising: a proximity sensor; and a memory for storing data; whereinthe proximity sensor detects whether the wearer is wearing the supportdevice and data produced by the proximity sensor is stored on thememory.
 10. The offloading support device of claim 1, further comprisinga blood flow stimulating system, wherein the blood flow stimulatingsystem comprises: a power supply; a fluid pump; a fluid reserve; acontroller; a bladder; and a proximity sensor, wherein the proximitysensor detects whether the offloading support device is being worn andthe controller is configured to disable the bladder when the proximitysensor does not detect that the support device is being worn.
 11. Theoffloading support device of claim 1, further comprising a temperaturesensor disposed within the boot, in or on the sole and/or the upper,configured to indicate a rise in temperature being indicative of skinbreakdown on the foot of the wearer of the support device.
 12. Theoffloading support device of claim 1, wherein the first and secondcoupling engagements are configured to prevent pressure hot spots on asole of the foot of the wearer.